9BCF

Chimeric protein of crocodile allergen Cro p 1.0101 and GFP

Summary for 9BCF

• Entry DOI: 10.2210/pdb9bcf/pdb
• Descriptor: Parvalbumin, Green fluorescent protein chimera, CALCIUM ION (3 entities in total)
• Functional Keywords: allergy, allergen
• Biological source: Crocodylus porosus (Australian saltwater crocodile); More
• Total number of polymer chains: 3
• Total formula weight: 119199.14

Authors

O'Malley, A.,Ruethers, T.,Lopata, A.L.,Chruszcz, M. (deposition date: 2024-04-09, release date: 2024-12-04, Last modification date: 2025-05-21)

Primary citation

O'Malley, A.,Ray, J.M.,Kitlas, P.,Ruethers, T.,Kapingidza, A.B.,Cierpicki, T.,Lopata, A.,Kowal, K.,Chruszcz, M.
Comparative studies of seafood and reptile alpha- and beta-parvalbumins.
Protein Sci., 33:e5226-e5226, 2024

PubMed Abstract: Small calcium-binding proteins such as parvalbumins (PVs) are major seafood and fish allergens. However, the impact of structural changes on their capacity to bind IgE has not been studied in detail. Therefore, fish and reptilian PVs, as well as human α-PV, were selected for biochemical, structural, and IgE binding studies. Likely due to their high solubility, crystallization proved difficult, so additional techniques were used to promote crystallization of the proteins. Novel crystal structures were determined for human PV, cod allergen Gad m 1.0201, saltwater crocodile allergen Cro p 1.0101, and the α-PV from thornback ray. β-PVs are considered the major fish allergens, while α-PVs are rarely categorized as allergens. To explain these differences, the results of structural and IgE binding studies were combined. This approach allowed us to provide new insight into IgE binding epitopes present on PVs, focusing on cross-reactivity among the selected α- and β-PVs. In addition, we have shown that these proteins display remarkable thermal stability across a range of pH conditions, which is relevant in the case of food allergens and food processing. Moreover, it is shown that the presence of calcium cations is critical for stability of the studied PVs via their protein folding, which has an impact on the formation of IgE binding epitopes. These studies shows the stability of fish and reptile PV allergens, and it allows for further evaluation of their IgE cross-reactivity.

PubMed: 39584689
DOI: 10.1002/pro.5226

Experimental method

X-RAY DIFFRACTION (3.2 Å)